Supplying ammunition to automatic guns



Jan. 12, 1960 R. G. VICKERS I 2,920,535

SUPPLYING AMMUNITION TO AUTOMATIC GUNS Filed April 2, 1958 4 Sheets-Sheet 1 INVEN'IOR ROY GIILBERI YICICERS BY an! "0! 3 7 ATTORNEYS Jan. 12, 1960 R. G. VICKERS SUPPLYING AMMUNITION TO'AUTOMATIC GUNS 4 Sheets-Sheet 2 Filed April 2, 1958 INVEN'IOR ROY GILBERT VICKERS ATTORNEYS Jan. 12,1960 R. G. VICKERS SUPPLYING AMMUNITION TO AUTOMATIC GUNS 4 Sheets-Shea; 3

Filed April 2. 1958 INVENTOR m m N? m A B Jan. 12, 1960 R.G.- VICKERS SUPPLXING AMMUNITION TO AUTOMATIC GUNS 4 Sheets-Sheet 4 Filed April 2, 1958 MN MW E QM S l J In Q9 a L I z 2 1 m w r w q R? Mo MN m m m ROY GILBERT ATTORNEYS SUPPLYING AMMUNITION TO AUTOMATIC GUNS Roy G. Vickers, Grantham, England, assignor to Brevets Aero-Mecaniques, S.A., Geneva, Switzerland, a corporation of Switzerland Application April 2, 1958, Serial No. 725,940 Claims priority, application Great Britain April 16, 1957 8 Claims. (Cl. 89-33) This invention relates to supplying ammunition to automatic guns of the kind, usually small calibre guns of say 20 mm. or 30 mm., for which ammunition rounds are formed into a belt by links interconnecting successive rounds in series side by side.

The links usually comprise C-shaped spring clips which simply grip frictionally around the cartridge case at about the mid-length of each round. As the rounds successively reach the breech mechanism of the gun, the links are separated from the rounds and are ejected.

Although care is taken, when belts of ammunition are made up, to ensure that the links are correctly positioned and the rounds are in alignment, it is found that rounds become misplaced in their links during travel of a belt of ammunition to a gun and any round out of alignment, by more than a small tolerance, is liable to cause jamming at the breech mechanism of the gun.

Misplacement of rounds in their links is partly due to the fact that the cartridge cases have a slight taper, so that the grip of the C-clips cannot be absolutely balanced, and also to drag of the rounds in the belt supply chute of the gun, which chute must often have bends and curves to lead the belt from a magazine or ammunition box to the gun. Also, the feed movement of the belt is not a steady continuous movement but a rapid step-by-step movement involving snatch and vibration along the length of the belt.

The object of the present invention is to ensure alignment of rounds, in feeding a linked ammunition belt to a gun, by a simple means which does not impose an undue frictional load on the movement of the belt.

According to the invention, in apparatus for guiding to an automatic gun an ammunition belt of interlinked rounds and including, in the path of the belt, a sprocket rotor the teeth of which engage the rounds successively, the sprocket rotor has a pair of sprockets which engage the links successively to hold them against lateral movement and, at the ends of the rotor, there is provided a pair of guides which are movable in the direction of feed of the belt and converge to form a pass defining the lateral limits of alignment of rounds in the belt.

The movable convergent guides provide low-friction abutments for the base or nose of any round out of alignment and the thrust of any such round against one or the other guide, as the belt is fed between the guides, moves the round endwise through its link, held by the sprockets, until the round is aligned at the pass between the guides.

The simplest form of movable convergent guides is a pair of discs, freely rotatably mounted on axes which cross, slightly obliquely, the ends of the axis of the sprocket rotor. The discs are thus almost coaxial with the sprocket rotor and can cooperate with a pair of sprockets, spaced apart along the axis of the rotor, so that, while the sprockets laterally hold each link of the belt in turn, the respective round is positioned between the discs. If the round is out of alignment, its base or 232,535 Patented Jan. 12, 1960 nose contacts the inner face of the respective disc, causes rotation of the disc in the direction of feed of the belt, and must move, endwise through its link and across the belt, before it can escape through the pass between the closest approach of the slightly oblique discs.

The invention is illustrated, by way of example, on the accompanying drawings, in which:

Fig. l is an elevation, from the front of the gun, of part of an ammunition supply chute which guides a belt of ammunition to an automatic gun.

Fig. 2 is a side elevation, in the direction of the arrow 11 in Fig. 1.

Fig. 3 is an axial plan section, on the line III--III in Fig. l, of the alignment unit assembly, and

Fig. 4 is a side elevation, partly in section, of an alternative mounting arrangement for the alignment unit assembly.

The part of an ammunition supply chute shown by Figs. 1 and 2, is carried by brackets 1 on the gun cradle, so that it moves with the gun in laying movement about the trunnion axis X-X.

A funnel 2 receives a belt of ammunition, from a relatively fixed part of the supply chute (not shown), and leads it to an alignment unit assembly, carried by bracket arms 3, from which it passes through a channel 4 to the breech feeding mechanism of the gun (not shown).

The belt of ammunition is of a Well-known kind, being made up of rounds 5 interconnected by links. Each link comprises a double clip 6 with two spaced C-shaped fingers, embracingone round and pivoted to a single clip 6", consisting of one C-shaped finger, embracing the next round. For convenience of illustration, the links are shown in full lines on two successive rounds, shown in broken lines, at the left-hand side of Fig. 3. Each round is gripped by a double clip 6 of one link and, between the fingers thereof, by the single clip 6 of the next link.

The alignment unit is shown in detail by Fig. 3 and includes a sprocket rotor which consists of a tubular hub 7 having three sprocket wheels 8, 9 and 10 fast thereon. Two of the sprocket wheels, 8 and 9, form a link-engaging pairand the third 10, having shallower troughs between its teeth, supports the projectile 5 which is of smaller diameter than the case 5', of each round in succession as the belt goes through.

As best seen in Fig. 2, the sprocket wheels 8 and 9 engage on either side of the double clip 6 of each successive link. The clips of successive links interdigitate, each clip 6 being between the fingers of the clip 6 of the next link, so that once the double clip 6 of the first link of a belt has been engaged laterally, by the sprocket wheels 8 and 9, all the remaining links must follow in alignment between the sprocket wheels 8 and 9.

Reverting to Fig. 3, the ends of the hub 7 are carried by the outer races of ball-bearings 11 on journals 12 of a fixed spindle 12. The spindle 12 also carries slightly oblique journals 12 for the inner races of ball-bearings 13 for a pair of guide discs 14 and 15. The opposed inner surfaces of the guide discs are made slightly frusto-conical so that corresponding radial lines (indicated by the lines R) of the discs at their line (P) of closest approach, where they form the alignment pass, are parallel and truly radial to the rotor axis.

The two rounds shown in broken lines at the left-hand side of Fig. 3, and which would in fact be above the plane of the section, indicate rounds which are laterally out of alignment in opposite directions. It will be seen, however, that their links are in alignment for engagement between the sprocket wheels 8 and 9 which hold the links laterally while the rounds pass between the inclined guide discs under the pull of the breech-feeding mechanism on the belt of ammunition. The guide discs 14 and 15 are freely rotatable, so that they move respectively with the base or nose of a round contacting them, but form convergingabutments against which the rounds must yield, by sliding endwise through the .clips oftheir links, before the rounds canpass between the closest approach of the guide discs and into the channel 4.

From the funnel 2 and through the channel 4, which is only a short part of the total ammunition supply path, the rounds are guided, with minimum frictional drag, by pairs of ribs 16 and 17. Consequently, the rounds which have been aligned by the guide discs are closely guided for their remaining short travel until they reach the gun which they enter in good parallel alignment;

An alternative'mounting arrangement for the alignment unit assembly is shown by Fig. 4. This arrangement, for I use in an ammunition supply system in which the belt cannot be supported throughout its path or in which the belt supply path is long, provides a resilient mounting which smooths out the step-by-step feed movement of the belt and thus decreases acceleration loads in the belt which might otherwise break at a link.

In Fig. 4, the fixed spindle 12 extends between the outer ends of a pair of lever arms 18 radiating parallel from the ends of a cross shaft 19 extending through and clamped axially to the inner members 20 of a pair of bonded rubber torsion sleeve mountings, of a well-known kind, the outer members 21 of which are clamped circumferentially in split casings 22 secured rigidly on the gun mounting.

At the ends of the spindle 12, the arms 18 carry a pair of part-cylindrical cowls 23 which retain the rounds in engagement with the sprockets and guide them circumferentially as they pass between the guide discs.

The arrangement of Fig. 4 can be used in place of an ordinary sprocket rotor for guiding a belt of ammunition in a loop or bend. In passing around the sprocket rotor, the rounds are aligned, in the same way as described above with reference to Figs. 1 to 3, and tension in the belt is automatically controlled by angular movement of the arms 18 in response to variation in pull along the belt. Stops may be provided for limiting angular movement of the arms 18 on their torsion sleeve mounting and such stops may include return stops located so that the rubber torsion sleeves are pre-loaded.

Although in the above described examples the movable convergent guides are simply and effectively provided by oblique, freely-rotatable discs, it will be apparent that other forms of such guides .could be used. For example, the discs could be replaced by a pairof convergent endless belts freely running around sleeve bearings or posts carried by the ends of the sprocket rotor mounting.

I claim:

1. Apparatus, for guiding to an automatic gun an ammunition belt composed of rounds interconnected by If V r I, 7 links, comprising a sprocket rotor, means for feeding said belt around said rotor, sprocket means on said rotor to engage said links successively and hold them against lateral movement as said belt is fed around said rotor, and a pair of guide means, one at each end of said rotor, movable and converging in the direction of feed of said belt to form a pass defining lateral limits of alignment of said rounds.

2. Apparatus'according to claim 1, in which said guide means consistof apair of circular discs freely rotatably mounted on axes'which cross, slightly obliquely, the ends of the axis of said rotor. v

3. Apparatus according to claim 2, in which said discs havelslightly frusto-conical opposed inner surfaces of which corresponding radial lines are parallel, as between one surface and the other, and are truly radial to the rotor axis .at a line of closest approach of said surfaces and at whichline said surfaces define said pass.

4. Apparatus according to claim 3 and-resilient mounting means supporting said rotor.

5. Apparatus according to claim -4, in which said re silient mounting means comprises a pair of lever arms between which said rotor is rotatably mounted and bonded-rubber torsion sleeve-means supporting said lever arms for resilient angular movement thereof.

6. Apparatus according to claim 1, and resilient mounting mean supporting-said rotor.

7. Apparatus, for guiding to an automatic gun an am munition belt composed of rounds interconnected by links,

comprising aspindle, a tubular hub rotatably mounted on said spindle, three sprocket wheels mounted fast on and spaced apart along said hub, two of said sprocket wheels being located and spaced apart to engage laterally said links and the third being ,locatedlto engage the projectile portion of each of said rounds, a pair of axially oblique journals, one at each end of said spindle,.and a pair of circular discs rotatably mountedrespectively one on each of said journals, said discs having slightlyfrustoconical opposedinner surfaces of which corresponding radial lines are parallel, as between one surface and the other, and are truly radial to the axis of said spindle at a line-of closest approach ofsaid surfaces.

8. Apparatus accordingto claim 7, a pair of lever arms between which said spindle is mountedand bonded rubber torsion'sleeve means supporting said lever arms ferresilient angular movement of said lever arms.

References Cited in the file oflthis patent UNITED STATES PATENTS Howe Sept. 28, 1943 Hepperle Ian. 22, 19 57 

